Apparatus for grinding, surfacing, and polishing the curved surfaces of lenses and the like



A. PASS Dec. 10, l 929.

APPARATUS FOR GRINDING, SURFACING, AND POLISHING THE CURVED SURFACES OF LENSES AND THE LIKE Filed June 28, 1928 3 Sheets-Sheet Dec. 10, 1929. A, PASS 1,739,086

APPARATUS FOR GRINDING, SURFACING, AND POLISHING THE CURVED SURFACES OF LENSES AND THE LIKE Filed June 28, 1928 5 Sheets-Sheet 2 F4 Fig. 2.

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APPARATUS FOR GRINDIN THE CURVED SURFACES OF LEN lA/VENTOP Patented Dec. 10, 1929 PATENT OFFICE Aitriitit PAs's, or 'izaooxsrnn, ENGLAND APPARATUS FOR enemas, seas mamh suns ine en's shaves SURFACES 0F nn'Ns'nsANn THE nixn apiineatibn filed June a,

This invention relates to apparatus for grinding, surfacing and polishing lensesand the like, and it has for its object to provide a reliable apparatus for producing a true parabolic surface and Whichmay be used for lenses of short focus and small diameter orfor lenses of long focus and large diameter.

1 attain this end by a construction which comprises essentially the use of a table to Which is secured a rod representing a dividingline between a pair of rods representing the angle of incidence and the angle of reflection or the lens to be ground surfaced or polished on 'Which table, for short focus crises, ismounted a rotary grindinglsurfacs ing or polishing apparatus hereinafter, for coiivenience of description, referred to as the grinding apparatus which Works on a lens rotatably mounted in a fixed position, or on which table, for long focus lenses, a rotary shaft is mounted and by Which the lens is carried adapted to be Worked onby a grind ing apparatus in a fixed position.

in the accompanyingdrawings which illusirate an embodiment of theinventi'on, Figure 1 is a diagrammatic view of the essential parts or the apparatus; Figure 2 is a a plan of the apparatus arranged for grinding small lenses; Figure 3 is a front 'elevationthereof; Figure 1 is a section on line ch /Figure 2; and Figure 5 is a front elevatienshowinl the main operative parts of the apparatus arranged for grinding large lenses;

The essential parts of an apparatus for carrying out thisinvention are shown in Fig ure 1 and comprise a table 1 pivotally mounted on a slide 2 mounted in guide Ways provided on a further slide 3 mounted in guide ways provided on a base 4. Rigidly secured to the table 1 isa rod 5, hereinafter "erred to the dividing rod. Rigidlfy s-eciired to the slide '3 is second rod 6, hereinaiter relierred to as the incidence rod, and a third rod 7, hereinafter referred toas the reflection rod, is p'ivotally inounted on a .part 8 slidably arranged on thebase l. The rods 6, and 7, when in a normal position, are an ranged parallel Withan d at tliesaine distance on either side of the rod-5, and are connected together by a rectangular frame composed of 1928. "Serial no. 283,984.

a plurality of links 9 of equal length, and, of the means for connecting said links to the rods, that located at 10 is lined to the rod 5 Whereas the others are free to slide on their respective reds. The table 1 is provided with a Wheel 11 adaptedto turn on the pivot pin 12 secured to the slide 2, The rear ends of the rods 6 and 7 are connected together by a band 13 passed around the Wheel 11 and a further band 1 1 connected at the points 15 and 16 on the rods 6 and 7, respectively, is passed around the opposite side or the Wheel 11-. The rod 7 is maintained in close contact With the side of the Wheel 11 by a suitably arranged spring 17. o

The normal position of the parts is indicated in-full lines and assuming the real focus to belocated at the point 18 on the dividing rod 5, by reason of the fact that the rods representing theangles of incidence and reflection are spaced apart, the nominal focus is located in a plane at right angles to the dividing rod 5 and at the point Where such line intersects the reflection rod, namely at the point of pivot 8.

If the slide 3 is moved in its guide Ways on the base din the direction of the arrow 19 th table 1 Will turn on its pivot and the slide 2 Will be drawn to the right, the path of movement of the pivot 12 is indicated. by the line 20 Which is a true parabolic curve. The position occupiediby the parts after the move ment above referred to is indicated by dotted lines. During the above described movement of the-slide Sironi the normal. position the rod '6 no independent movement apart therefrom and as the rod 7 has only a pivotal movement on the base 1 the Wheel 11, by reasonof the bands 13 and is connected to the rods 6 andi', is drawn to the rigl'it along the rod 6 thereby causing the slide 2 to move in the same direction. It will be understood that immediately the parts are moved from the normal position the angle 8 formed between the dividing rod 5) and the incidence rod 6 on the one side and that formed between the dividing rod '5 and the reflection rod 7 on the other side must always be equal by reason of the connecting links 9,

and any part mounted on the table 1 must necessarily move in a parabolic curve.

Having thus briefly described the essential principles upon which this invention is based a form of apparatus embodying the essential parts diagrammatically illustrated in Figure 1 will now be described, the same numerals of reference being employed for indicating said essential parts.

The apparatus comprises a base plate 4 and arranged near one end thereof and at right angles thereto is a second plate 3 arranged to be traversed in guide ways 21 by a hand wheel 22 and screwed rod23 in the known manner. Superimposed on the plate 3 is a further plate 2, traversed in guide ways 24 arranged at right angles to the direction of movement of the plate 3. Pivotally mounted on the plate 2 is a carrier table 1 to one end of which is securely fixed the dividing rod 5. The incidence rod 6 is securely fixed to the plate 3 in the part 25 said rod being adapted when the parts are in normal or central position, which is equivalent to the axis of the lens, to take a position parallel to the dividing rod 5. The reflection rod 7 is arranged on the other side of the dividing rod 5, said rod 7 being arranged parallel to said dividing rod 5 and at the same distance therefrom as the incidence rod 6.. The rod 7 is secured to a part 8, representin the nominal focusof the lens to be operate on, 'pivotally carried by a part 26 adjustably mounted in a slot 27 providedin the base plate 4, said slot being arranged parallel to the normal position of the dividing rod 5. e I i The dividing'rod 5 is provided with two elements 28 and 29, the element 28 being secured to the rod 5 at a point near its fixed end and the element 29 is located near the opposite end and is free to slide thereon. Elements 31 and 32, similar to the elements 28 and 29 are slidably mounted on the rods 6 and 7 and the four elements are connected together as shown in Figures 1 and 2'by a plurality of links 9 of equal length. The carrier table 1 is furnished with a grooved wheel 11 around which are placed two inextensible bands 13 and 14. The band 13 is suitably connected to the extreme ends of the rods 6 and 7 and the band 14 is suitably connected to said rods at convenient points traversed by a hand wheel 36 and screwed rod 36 and the plate 36 is provided with guide ways 37 arranged at right angles to the guide ways 35 in which is adapted to slide a plate 38 traversed by a hand wheel 39 and screwed rod 40, on which plate is pivoted a suitable support 41 adapted, when operating on short focus lenses, to carry a shaft 42 on one end of which is secured a grinding wheel 43, and a driving pulley 44 at the other. The shaft 42 may be driven in any convenient manner such as by a small motor mounted on the apparatus or from an overhead shaft. The support 41 is adapted to be moved through an angle of 90 and for this purpose a slot 45 is provided in the base plate 46 of said support to receive a pin 47 fixed in theplate 38 the upper end of said pin being provided with a nut 48 by which the base plate .46 and thereby the support 41 is secured in the desired position.

A suitably shaped framework 49 is mounted on the base plate 4, said framework being arranged transversely above the rods 5, 6 and 7, and said framework is preferably but not necessarily adjustably secured to said'base plate 4 by bolts 50 located in slots '51 provided in the base plate 4 so that its position on said base plate relatively to the support 41 may be varied as desired. Immediately above the dividing rod 5 on the upper face of the framework 49 is a plate 52 slidably arranged in guide ways 53 forming part of the framework 49. The plate 52 is traversed in the guide ways 53 by means of the hand wheel 54 and screwed rod 55. Mounted on or forming part of the plate 52 is a support 56 in the upper part of which is mounted a shaft 57 on one end of which is secured a plate 58 upon which the lens 59 to be ground is adapted to be mounted, and on the other end of such shaft is a pulley 60 by means of which the shaft 57 maybe driven by any suitable means such as a small motor mounted on the apparatus or from an overhead shaft. The axis of the shaft 57 is located in the same vertical plane as the normal axis of the dividing rod 5 and coincident or coaxial with the normal axis of the shaft 42 and thereby with the axis of the grinding wheel 43.

When the parts are in position shown in Figures 2, 3 and 4, and the lens carrier has been brought up so that the grinder 43 may act on said lens, the plate 3 is moved in the direction of the arrow 19 (Figure 2) which thereby causes the grinder to be traversed in a similar direction but in a parabolic path.

To impart a true parabolic curve to a lens it necessarily requires perfect fitting of the various slides in their guide ways.

When it is desired to grind large lenses, the parts are arranged as diagrammatically shown in Figure 5. In this case the plate 36 (and the parts carried thereby) is removed from the guide ways 35 and the plate 52 (and the parts carried thereby) removed from the guide ways 53, is substituted therefor. The plate 38 (and the parts carried thereby) removed from the guide Ways 37 is placed in the guide ways 61 transversely arranged on an extension of the base plate 4.

When the parts are arranged in this position the lens to be operated on is traversed in a parabolic path across the face of the grinder and it neccessarily follows that the surface ground on said lens must also be a true parabolic curve.

While it is possible to construct an apparatus for working on both small and large lenses as above described, for reasons of economy and simplification of construction, it would be preferable to construct two independent apparatus, viz: one for grinding small lenses and one for grinding large lenses.

What I claim is 1. An apparatus for grinding surfacing and polishing lenses and the like comprising in combination a base plate, a support for the lenses to be operated upon, a support for the grinding element, a table upon which one of said supports is mounted, sliding elements upon which said table is mounted, means for imparting a sliding movement to said sliding elements, a rod secured to said table, a pair of rods arranged one on each side of said first named rod, one of said rods being secured to one of the sliding elements, the other being pivoted to the base plate, said rods being so mounted and connected together that when the means for imparting a sliding movement to the sliding elements is operated the table and the parts carried thereby are caused to move in a parabolic curve.

2. An apparatus for grinding surfacing and polishing lenses and the like comprising in combination a support for the lens to be operated upon, a support for the grinding element, a table upon which one of said supports is mounted, sliding elements upon which said table is mounted, means for imparting a sliding movement to said sliding elements, a rod secured to said table, a pair of rods arranged one on each side of said first named rod, means connecting said rods together comprising a rectangular frame composed of a plurality of links of equal length four elements on which said links are pivoted, one of said elements being secured to the first named rod, another slidable thereon and one element slidable on each of said other rods, the arrangement being such that when movement is imparted to the sliding elements the links cause the second named rods to maintain an equal angle with and relatively to the central rod and cause the table to which the lat-- ter is connected to move in a parabolic curve.

3. An apparatus for grinding surfacing and polishing lenses and the like comprising a table, a slide, a vertically disposed pin carried by said slide upon which said table is nd nnected t" said second and d, rods ahdlpassing around said i 1 l oppositesidtnmeans formalinfeti e I. v I

when; his ns for etp rti g a end- Tr ap d A iportn'lg the lens b kdonfbysdid riding apparatus i ofsai dsupporting M i w 1 u u, w L H, 1M J P, i 1 i i i the third named rod in close com act 4- 1 i M 'l 1n i'atus, means fol 911 vely to th other through aparabolic path i app a i alilsfor grinding surfacing and polishing lenses and the like comprising a table, a slide, a pin carried by said slide upon which said table is pivoted, a second slide arranged at right angles to the first named slide, guide ways secured to said second slide in which the first named slide reciprocates, a base plate, guide ways secured to said base plate in which the second named slide reciprocates, a rod rigidly secured to said table, a rod rigidly secured to the second slide, a part adjustably mounted on said base plate, a rod pivotally mounted on said part, means for connecting the three rods together so that the second and third named rods always occupy the same position relatively to the first named rod, a wheel rotatably mounted above the table on the pivot pin carried by the first named slide, a band connecting the rear ends of the second and third named rods and passing around said wheel, a second hand connected to said second and third named rods and passing around said wheel on the opposite side, means for maintaining the third named rod in close contact with the wheel, means for supporting a rotatable carrier on which the lens to be worked on is mounted, means for supporting a rotatable carrier on which the grinding apparatus is mounted and means for moving one of said carriers relatively to the other through a parabolic path.

5. An apparatus forgrindingsurfacingand polishing lenses and the like comprising a table, a slide, a pin carried by said slide upon which said table is pivoted, a second slide arranged at right angles to the first named slide, guide ways secured to said second slide in which the first named'slide reciprocates, a base late, guideways secured to said base plate in which the second named slide reciprocates a rod rigidl'ysecured to said'table, a rod rigidly secured to the second slide, a part adjustably mounted on said base plate, a rod pivotally mounted on said part, means for connecting the three rods together so that the second and third named rods always occupy the same position relatively to the first I opposite side, means for maintaining the third I named rod in close contact with the wheel, means comprising an adjustable support for a rotatable shaft .on which the lens to be worked on is mounted, means comprising an adjustable support for a rotatable shaft on which the grinding ap aratus I is mounted and means for traversm onelof said adjustable supports in a parabo ie other adjustable support. I

- ARTHUR PASS.

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